The amp really does shine with classical music. I think Steve on the Decware site really does explain well in the owner's manual of the ZenHead the non-fatiguing sound signature he was after.
I have been reading posts in Head Fi off and on for over two years and a common complaint I have heard again and again is that the 2005 Beyer DT 880's are "too bright" and "too sibilant". It struck me today that real problem has been that the Beyer's aren't "too bright" but that most portable amplifers are too fatiguing because too much high frequency material is brought to foreground of the soundstage as a consequence of decisions made by the designers of most portable amplifiers.
If you already own a pair of Beyer DT 880's, you really owe it too yourself to try them with a ZenHead.
Side note. If anyone is interested in listening to FM Radio during the day (I enjoy listening to NPR) here is a moderately priced Sony Portable FM Tuner that works well with the ZenHead. Sony SRF-M37V as a tiny source of FM.
Amazon.com: Sony: Electronics SFR-M37V-Weather-Walkman-Presets/dp/B00008W7LS
Here is what Dr. Xin has to say about the Sony SFR-M37V on his website.
Pocket radio, the best gift for Dad!
This portable FM Radio also sounds very very good with my Shure SE310 IEM's.